diff options
author | John Newbery <john@johnnewbery.com> | 2019-07-23 11:49:53 -0400 |
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committer | Antoine Riard <ariard@student.42.fr> | 2019-08-01 13:43:29 -0400 |
commit | fb62f128bbfd8c6cd72ea8e23331a4bae23883ab (patch) | |
tree | 55008efc4536f40f59177f33e5faa6d886a40a27 /src | |
parent | b8eecf8e79dad92ff07b851b1b29c2a66546bbc1 (diff) | |
download | bitcoin-fb62f128bbfd8c6cd72ea8e23331a4bae23883ab.tar.xz |
Tidy up BroadcastTransaction()
Diffstat (limited to 'src')
-rw-r--r-- | src/node/transaction.cpp | 37 | ||||
-rw-r--r-- | src/node/transaction.h | 9 |
2 files changed, 30 insertions, 16 deletions
diff --git a/src/node/transaction.cpp b/src/node/transaction.cpp index 0cbf645984..8e56496358 100644 --- a/src/node/transaction.cpp +++ b/src/node/transaction.cpp @@ -23,15 +23,17 @@ TransactionError BroadcastTransaction(const CTransactionRef tx, std::string& err { // cs_main scope LOCK(cs_main); + // If the transaction is already confirmed in the chain, don't do anything + // and return early. CCoinsViewCache &view = *pcoinsTip; - bool fHaveChain = false; - for (size_t o = 0; !fHaveChain && o < tx->vout.size(); o++) { + for (size_t o = 0; o < tx->vout.size(); o++) { const Coin& existingCoin = view.AccessCoin(COutPoint(hashTx, o)); - fHaveChain = !existingCoin.IsSpent(); + // IsSpent doesnt mean the coin is spent, it means the output doesnt' exist. + // So if the output does exist, then this transaction exists in the chain. + if (!existingCoin.IsSpent()) return TransactionError::ALREADY_IN_CHAIN; } - bool fHaveMempool = mempool.exists(hashTx); - if (!fHaveMempool && !fHaveChain) { - // push to local node and sync with wallets + if (!mempool.exists(hashTx)) { + // Transaction is not already in the mempool. Submit it. CValidationState state; bool fMissingInputs; if (!AcceptToMemoryPool(mempool, state, std::move(tx), &fMissingInputs, @@ -46,24 +48,31 @@ TransactionError BroadcastTransaction(const CTransactionRef tx, std::string& err err_string = FormatStateMessage(state); return TransactionError::MEMPOOL_ERROR; } - } else if (wait_callback) { - // If wallet is enabled, ensure that the wallet has been made aware - // of the new transaction prior to returning. This prevents a race - // where a user might call sendrawtransaction with a transaction - // to/from their wallet, immediately call some wallet RPC, and get - // a stale result because callbacks have not yet been processed. + } + + // Transaction was accepted to the mempool. + + if (wait_callback) { + // For transactions broadcast from outside the wallet, make sure + // that the wallet has been notified of the transaction before + // continuing. + // + // This prevents a race where a user might call sendrawtransaction + // with a transaction to/from their wallet, immediately call some + // wallet RPC, and get a stale result because callbacks have not + // yet been processed. CallFunctionInValidationInterfaceQueue([&promise] { promise.set_value(); }); callback_set = true; } - } else if (fHaveChain) { - return TransactionError::ALREADY_IN_CHAIN; } } // cs_main if (callback_set) { + // Wait until Validation Interface clients have been notified of the + // transaction entering the mempool. promise.get_future().wait(); } diff --git a/src/node/transaction.h b/src/node/transaction.h index 08ceace7f8..cf64fc28d9 100644 --- a/src/node/transaction.h +++ b/src/node/transaction.h @@ -11,14 +11,19 @@ #include <util/error.h> /** - * Broadcast a transaction + * Submit a transaction to the mempool and (optionally) relay it to all P2P peers. + * + * Mempool submission can be synchronous (will await mempool entry notification + * over the CValidationInterface) or asynchronous (will submit and not wait for + * notification), depending on the value of wait_callback. wait_callback MUST + * NOT be set while cs_main, cs_mempool or cs_wallet are held to avoid + * deadlock. * * @param[in] tx the transaction to broadcast * @param[out] &err_string reference to std::string to fill with error string if available * @param[in] max_tx_fee reject txs with fees higher than this (if 0, accept any fee) * @param[in] relay flag if both mempool insertion and p2p relay are requested * @param[in] wait_callback, wait until callbacks have been processed to avoid stale result due to a sequentially RPC. - * It MUST NOT be set while cs_main, cs_mempool or cs_wallet are held to avoid deadlock * return error */ NODISCARD TransactionError BroadcastTransaction(CTransactionRef tx, std::string& err_string, const CAmount& max_tx_fee, bool relay, bool wait_callback); |